Power integrated circuit (IC) chip assembly and manufacturing generally includes applying a controlled amount of a soldering element, such as but not limited to, a soldering paste to attach at least one electrical component to a substrate. The electrical components may include, but are not limited to, transistors (such as, but not limited to, metal oxide semiconductor field-effect transistor, MOSFET), diodes and resistors. The IC chip is assembled with the electrical component using the soldering paste or solder element. Once the chip is assembled, it is then subjected to a controlled heat, which melts the soldering element, thereby forming a permanent electrical connection between the component and the substrate. The application of heat is typically conducted in a reflow oven, which melts the solder without damaging the adjoining areas and the attached electrical components.
Due to decreases in package size of the IC chip assembly and with the increase of power levels in electrical applications, the IC chip package requires near perfect void-free soldered connections. However, the quality of the connections may be negatively affected by the introduction of unwanted gases released during the application of heat in the fusing process. These unwanted gases are typically enhanced due to the solders used in the process and should be minimized to protect the environment and operators by limiting harmful emissions.
However, the use of the reflow ovens alone may not decrease the voids and may result in additional unwanted voids in the soldered connection. In certain applications, such as, automotive battery controllers, these voids may cause overheating of the IC chip where a high power MOSFET is used to control increased power levels. In such applications, the process of assembling and manufacturing the IC MOSFET chip may include the application of a vacuum source to aid in the removal of any voids or air pockets in the soldered connection.
Generally, such an application of vacuum is conducted through the use of a stand-alone unit, which includes three separate and distinct process chambers for pre-heating, soldering and cooling. The three separate process chambers are divided within an enclosure and may be loaded either manually by an operator or automatically with manipulators. The systems include a vacuum system for applying a vacuum within the cabinet. The vacuum is applied to a process atmosphere in each process chamber. These systems are costly and cannot be used with nor do they require an additional reflow oven pallet/conveyor system. Thus, there is a need in IC MOSFET chip manufacturing for a cost effective device and method for applying a vacuum during the soldering process while utilizing a standard reflow oven system.